USB: ohci-nxp: Rename symbols from pnx4008 to nxp

Since this driver is compatible with several NXP devices, the driver was renamed
accordingly. This patch also changes the respective symbol names.

Signed-off-by: Roland Stigge <stigge@antcom.de>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>